| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for determining an ink ejection state of a recording head, which is capable of accurately and timely determining an ejection state of each nozzle, while inhibiting the recorder from getting large in size and increasing in cost.SOLUTION: The recording head includes a plurality of constitutions where a heater provided in a nozzle for ejecting ink and a temperature sensor are adjacently provided one to one. When the recording head is driven, the temporal change of detected temperature by the temperature sensor is monitored, and in a temperature drop process of the heater, temperature at a plurality of points in a predetermined section of time including timing that the feature of the temporal change of the detected temperature, which is made when the ink is normally ejected, appears is extracted. Next, a second derivative concerning the time of the extracted temperature is calculated, and calculated values are added to obtain the sum total and an intermediate accumulated value. The sum total is compared with predetermined first threshold and second threshold to determine whether the ink is normally ejected or defectively ejected. If it can not be determined by such comparison, the intermediate accumulated value is compared with a predetermined third threshold to finally determine whether the ink is normally ejected or defectively ejected. |
